The German finance minister, Wolfgang Schäuble, said he had ‘no concerns’ about Deutsche Bank.
Photograph: Kai Pfaffenbach/Reuters

German’s finance minister and the chief executive of Deutsche Bank have both attempted to allay concerns about the health of Germany’s biggest lender as its shares kept falling on another day of financial market turmoil that left London’s stock market at its lowest level for more than three years.

But their efforts failed to stem the slide in Deutsche’s shares, which fell another 5% on Tuesday, on top of Monday’s 9.5% fall. The shares have now lost more than 40% this year in turbulent markets hit by fears about the growth prospects for the global economy and the implications of the low price of oil and prolonged low interest rates.

In London, a 1% fall in the FTSE 100 index pushed it to 5632 at the close, its lowest close since November 2012, although that was higher than the low point of the day – 5596. The mood for the trading day had been set by an overnight plunge in Japan, where the Nikkei index suffered its biggest one-day fall in three years. A loss of 918 points left it 5.5% down at 16,085.

Cryan’s personal interventioncame after an emergency announcement late on Monday that was intended to calm investor concerns that it might not be able to make payments on a special kind of debt that converts into shares during times of crisis.

Concerns about Deutsche have swirled since January, when the bank reported its first full-year loss since 2008. It came during a restructuring and the possibility of further hefty fines from regulators.

In his email, Cryan, who is attempting to overhaul Deutsche, said: “The management board talked about progress on our strategy, and how recent market volatility and forecasts for slowing economic growth might impact our clients and us. Volatility in the fourth quarter impacted the earnings of most major banks, especially those in Europe, and clients may ask you about how the market-wide volatility is impacting Deutsche Bank.

“You can tell them that Deutsche Bank remains absolutely rock solid, given our strong capital and risk position. On Monday, we took advantage of this strength to reassure the market of our capacity and commitment to pay coupons to investors who hold our Additional Tier 1 capital. This type of instrument has been the subject of recent market concern.”

The chief executive, who is British and has spent much of his career at the Swiss bank UBS, said the bank did not share the market’s concern about whether it had set aside funds to cover fines and other legal matters. “We will almost certainly have to add to our legal provisions this year but this is already accounted for in our financial plan.”